The present invention relates generally to a chassis arrangement for carrying the mechanism of a magnetic recording and reproducing apparatus, and more particularly to a chassis arrangement which contributes to improved productivity and is suitable for automated assembly.
FIG. 7 illustrates one example of a prior-art chassis arrangement for carrying the mechanism of a typical magnetic recording and reproducing apparatus which is a helical scan VTR (video tape recorder). As shown, the prior-art chassis arrangement typically includes: a cassette loading device 8; Hall elements 18, 19 for detecting the respective rotations of associated reels; a light-emitting element 20 and a light-receiving element 21a for cooperating with each other in detecting a transparent leader tape; a safety switch 23 for operatively detecting the safety lug of a tape cassette so as to prevent erroneous erasure of the recorded contents of a magnetic recording tape; a mode select switch 24 associated with various operating modes of the mechanism; cassette detecting switches 36, 37 for controlling the position and transportation of a tape cassette; connectors 40; and leads 41. As is evident from FIG. 7, a majority of the aforesaid components such as the detecting Hall elements 18, 19, the light-emitting element 20, the light-receiving element 21a, the safety switch 23, the mode select switch 24 and the cassette detecting switches 36, 37 are separately mounted on either the chassis for carrying the mechanism or the cassette loading device 8. These elements and switches are connected via a substrate and the connectors 40 to the leads 41 for signal communication with signal circuits, printed circuits and the like which are provided within the body of the apparatus. In this arrangement, the connectors 40 and the substrate must be connected to the individual positions occupied by the aforesaid detecting elements and switches, and this leads to the disadvantage that the amount of work involved increases accordingly. In addition, the arrangement of each individual lead needs to be considered, and in particular further consideration must be given to the arrangement of leads located adjacent to movable members of the mechanism. This in turn involves a remarkably large amount of work.
To obviate these disadvantages, Japanese Utility model Laid-open No. 23789/84 previously proposes a chassis for an electronic appliance comprising a framework made of sheet metal covered with an insulating layer on which a printed wiring pattern is formed. This arrangement involves remarkably expensive production costs, and in addition, if a portion of the wiring pattern formed in the chassis is broken or other similar drawbacks occur, once all the parts mounted on the chassis have been removed from such defective chassis, the chassis must be replaced with a new one, and thereafter, the thus-removed parts are again assembled with the new chassis. This may also offer a problem to efficient maintenance.